[Static Runtime] Remove unnecessary fb::equally_split nodes (#64022)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/64022
Test Plan: - Added unittest `StaticRuntime.RemoveEquallySplitListUnpack`.
Reviewed By: hlu1
Differential Revision: D30472189
fbshipit-source-id: 36040b0146f4be9d0d0fda293f7205f43aad0b87
